A guitar's unique tone and playability is the result of many factors, including the type and configuration of the guitar bridge and saddles. For example, Stratocaster style guitars are traditionally equipped with either a tremolo bridge or a fixed-tail bridge. Characteristics of both types of bridges impact the overall tone of the guitar in recognizable ways. In addition, both types of bridges offer unique playability characteristics, related to tuning stability and tremolo functionality.
The fixed-tail guitar bridge typically includes a bridge plate and string saddles. The bridge plate attaches directly to the front of the guitar body such that the bridge plate does not move relative to the guitar body. Guitar strings are installed either through the end of the bridge plate or through the back of the guitar body, via string ferrules. Because of the fixed position of the bridge plate, and the stable attachment of the bridge plate to the guitar body, a guitar equipped with a fixed-tail bridge offers greater tuning stability than a guitar with a pivoting bridge, such as a tremolo bridge. However, the fixed-tail bridge does not utilize a sustain block or springs.
A tremolo bridge for a Stratocaster style guitar typically includes a bridge plate, a sustain block, springs, and a tremolo bar. One end of the bridge plate is beveled to allow the bridge plate to pivot or rock. Bridge mounting screws attach the beveled end of the bridge plate to the front of the guitar body via bridge mounting holes on the beveled end. The bridge mounting screws are configured such that a smooth shank portion of the screw is exposed above the guitar body and below the screw head. When the bridge plate pivots, the bridge mounting holes slide on the smooth shank portions of the bridge mounting screws.
The tremolo bar is received through an aperture in the bridge plate by a sustain block that is attached to the bridge plate and positioned in a cavity within the guitar body. The bridge plate is asymmetrically designed, with a greater portion of the bridge plate on the side of the tremolo bar to allow for the aperture through which the tremolo attaches to the sustain block.
Guitar strings on a guitar with a tremolo bridge are installed through the sustain block and bridge plate. The guitar strings are fed through string saddles attached to the guitar bridge. Traditionally, the strings are fed through grooves or channels in the string saddles. At the other end of the guitar, the guitar strings are fed through a nut and string trees and attached to tuning keys on the head stock. The portion of the guitar string between the string saddles and the nut vibrates when plucked or strummed producing the guitar's sound. When the guitar player frets a note, the vibrating portion of the string between the fret and the string saddle produces the sound. The material and shape of the string saddles, nut, and frets each affect the tone of the guitar in recognizable ways.
Springs attached to the sustain block impart a biasing force on the sustain block, and bridge plate, returning the bridge plate to a flat position relative to the guitar body when the tremolo bar is not being operated. When the tremolo bar is operated, the sustain block and bridge plate pivot and the pitch of the note being played is lowered. The tremolo bar may be operated by successive pushing and releasing to achieve a vibrato effect.
While the sustain block and springs are integral to the operation of the tremolo bar, each contributes in a recognizable way to the overall tone of the guitar even when the tremolo bar is not operated. For example, the sustain block increases the resonance of a note being played, while the springs increase the reverberation of the note. Thus, the tone enhancing effects of the sustain block and tension springs are desirable characteristics of the tremolo bridge aside from the tremolo bar functionality.
Further, the pivoting aspect of the bridge plate is often an undesirable characteristic of the tremolo bridge. Guitars with a tremolo bridge are more difficult to keep in tune than guitars equipped with a fixed-tail bridge. Guitars with a tremolo bridge must be retuned frequently during a performance. In addition, depending on the musical setting, the vibrato effect accomplished by the tremolo bar may not be musically appropriate.
For these reasons, the tremolo bar is often removed completely from the tremolo bridge. Removal of the tremolo bar, however, leaves the aperture on the bridge plate exposed, which may be aesthetically displeasing. Removal of the bar leaves the asymmetrical bridge plate exposed as well, which may also be aesthetically displeasing.
In addition to removing the tremolo bar, the sustain block is often “blocked” by a wood block, wedge, or shim within the sustain block cavity. Blocking the sustain block prevents the rocking action of the tremolo bridge. (Eric Clapton is said to have blocked the sustain block of the tremolo bridge on his Stratocaster.) The bridge plate remains attached to the face of the guitar by the bridge plate mounting screws on the beveled edge which are configured to allow for pivoting of the bridge plate. These pivoting features are undesirable, and unnecessary, when the sustain block has been blocked to prevent pivoting of the bridge plate.
Thus, an aesthetically desirable bridge with the tuning stability of a fixed-tail bridge and the tone enhanced characteristics of a tremolo bridge is needed.